And use of a leg support exoskeleton

Abstract

A leg support exoskeleton is strapped on as wearable device to support its user during squatting. The exoskeleton includes a knee joint connected to a first line and a second link, which is configured to allow flexion and extension motion between the first link and the second link. A force generator has a first end that is rotatably connected to the first link. A constraining mechanism is connected to the second link and has at least two operational positions. In a first operational position, the second end of the force generator engages the constraining mechanism, where the first link and the second link flex relative to each other. In a second operational position, the second end of the force generator does not engage the constraining mechanism; the first link and the second link are free to flex and extend relative to each other.

What is claimed: 
     
       1. A leg apparatus configured to be coupled to a leg of a wearer, the leg apparatus comprising:
 a first link; 
 a second link, coupled to the first link and capable of flexion and extension motion relative the first link; 
 a force generator, comprising a first end and a second end, wherein the first end of the force generator is coupled to the first link; 
 a constraining mechanism, having at least a first operational position and a second operational position; and 
 an actuator, operable to move the constraining mechanism between the first operational position mode and the second operational position, 
 wherein:
 when the actuator moves the constraining mechanism into the first operational position, the second end of the force generator is engaged with the second link and the force generator provides a resistance torque in response to flexion of the first link and the second link relative to each other, and 
 when the actuator moves the constraining mechanism into the second operational position, the second end of the force generator is disengaged from the second link, and the first link and the second link are free to flex and extend relative to each other. 
 
 
     
     
       2. The leg apparatus of  claim 1 , further comprising a triggering mechanism configured to automatically move the constraining mechanism between the first operational position and the second operational position, wherein the triggering mechanism comprises:
 a stance detector, configured to detect if the leg of the wearer is in contact a ground; 
 a transmission line, comprising a first end and a second end, the first end coupled to the constraining mechanism, and the second end coupled to the stance detector; and 
 a return spring, mounted on the second link and coupled to the transmission line, 
 wherein:
 when the leg of the wearer is in contact with the ground, the stance detector is configured to move the constraining mechanism to the first operational position through the transmission line, and 
 when the leg of the wearer is not in contact with the ground, the return spring is configured to move the constraining mechanism to the second operational position. 
 
 
     
     
       3. The leg apparatus of  claim 2 , wherein the transmission line is selected from the group consisting of a rope, a wire rope, a twine, a thread, a nylon rope, a chain, a rod, and any combination thereof. 
     
     
       4. The leg apparatus of  claim 2 ,
 wherein the transmission line is a hydraulic hose containing hydraulic fluid, 
 wherein the stance detector comprises a reservoir containing the hydraulic fluid, and 
 wherein:
 when the leg of the wearer is in contact with the ground, pressure generated in the hydraulic fluid due to contact of the leg apparatus with the ground is configured to move the constraining mechanism to the first operational position through the hydraulic hose, and 
 when the leg of the wearer is not in contact with the ground, the return spring is configured to move the constraining mechanism to the second operational position. 
 
 
     
     
       5. The leg apparatus of  claim 2 , wherein the stance detector is located in a location selected from the group consisting of inside a shoe of the wearer, at a bottom of the shoe of the wearer, in a sole of the shoe of the wearer, and any combination thereof. 
     
     
       6. The leg apparatus of  claim 1 , wherein the constraining mechanism comprises:
 a pawl, coupled to the second link and having at least a first position during the first operational position and a second position during the second operational position, and 
 a sliding ratchet, rotatably coupled to the second end of the force generator, 
 wherein in the first position, the pawl constrains the sliding ratchet from sliding on the second link, and 
 wherein in the second position, the pawl allows the sliding ratchet to freely slide on the second link. 
 
     
     
       7. The leg apparatus of  claim 6 , wherein the actuator is configured to move the pawl between the first position and the second position. 
     
     
       8. The leg apparatus of  claim 1  further comprising a triggering mechanism configured to automatically move the constraining mechanism between the first operational position and the second operational position,
 wherein the triggering mechanism comprises:
 an actuator, configured to move the constraining mechanism between the first operational position and the second operational position; and 
 a stance sensor, configured to detect if the leg of the wearer is in contact with a ground and to generate a first electric signal when the leg of the wearer is in contact with the ground and to generate a second electric signal when the leg of the wearer is not in contact with the ground, 
 when the leg of the wearer is contacting the ground, the stance sensor generates the first electric signal, and the actuator is configured to move the constraining mechanism to the first operational position, and 
 when the leg of the wearer is not contacting the ground, the stance sensor generates the second electric signal, and the actuator is configured to move the constraining mechanism to the second operational position. 
 
 
     
     
       9. The leg apparatus of  claim 8 , wherein the stance sensor is selected from the group consisting of a strain gage sensor, a pressure sensor, a force sensor, a piezoelectric force sensor, a force sensor based on force sensing resistors, and any combination thereof. 
     
     
       10. The leg apparatus of  claim 1 , wherein the constraining mechanism is configured to move into the first operational position when the leg of the wearer is on a ground. 
     
     
       11. The leg apparatus of  claim 1 , further comprising at least one stance detector, configured to generate a stance signal, wherein the constraining mechanism moves to the first operational position if the stance detector declares the leg of the wearer being on a ground. 
     
     
       12. The leg apparatus of  claim 1 , wherein the constraining mechanism comprises:
 an indentation; and 
 an indentation filler, coupled to the second link and having at least a first operational position mode and a second operational position mode, 
 wherein:
 when the indentation filler is in the first operational mode, the indentation is not occupied by the indentation filler and the second end of the force generator is engaged with the indentation when the first link and the second link flex relative to each other, and 
 when the indentation filler is in the second operational mode, the indentation is occupied by the indentation filler, the second end of the force generator disengaged from the indentation, and the first link and the second link are free to flex and extend relative to each other. 
 
 
     
     
       13. The leg apparatus of  claim 1 , wherein one of the first link or the second link is configured to be coupled to a thigh of the wearer. 
     
     
       14. The leg apparatus of  claim 1 , wherein one of the first link or the second link is configured to be coupled with a shank of the wearer. 
     
     
       15. The leg apparatus of  claim 1 , wherein the force generator is selected from the group consisting of a gas spring, a compression spring, a coil spring, a leaf spring, an air spring, a tensile spring, and a combination thereof. 
     
     
       16. A leg apparatus configured to be coupled to a leg of a wearer, the leg apparatus comprising:
 a first link; 
 a second link, coupled to the first link and capable of flexion and extension motion relative the first link; and 
 a force generator, comprising a first end and a second end wherein the first end of the force generator is coupled to the first link, 
 wherein
 while the leg of the wearer is on a ground, the second end of the force generator is automatically engaged with the second link when the first link and the second link flex relative to each other, and 
 while the leg of the wearer is not on the ground, the second end of the force generator is disengaged from the second link, and the first link and the second link are free to flex and extend relative to each other. 
 
 
     
     
       17. The leg apparatus of  claim 16  further comprising a stance sensor, configured to detect if the leg of the wearer is in contact with the ground and to generate a first electric signal when the leg of the wearer is in contact with the ground and to generate a second electric signal when the leg of the wearer is not in contact with the ground. 
     
     
       18. The leg apparatus of  claim 17 , wherein the stance detector is located in a location selected from the group consisting of inside a shoe of the wearer, at a bottom of the shoe of the wearer, in a sole of the shoe of the wearer, and any combination thereof. 
     
     
       19. The leg apparatus of  claim 16 , wherein one of the first link or the second link is configured to be coupled to a thigh of the wearer. 
     
     
       20. The leg apparatus of  claim 16 , wherein one of the first link or the second link is configured to be coupled with a shank of the wearer. 
     
     
       21. A leg apparatus configured to be coupled to a leg of a wearer, the leg apparatus comprising:
 a first link; 
 a second link, coupled to the first link and capable of flexion and extension motion relative the first link; 
 a force generator, comprising a first end and a second end, wherein the first end of the force generator is coupled to the first link; and 
 a manual tab, having at least a first position and a second position and operable by the wearer, wherein:
 when the manual tab is in the first position, the second end of the force generator engages with the second link and the force generator provides a resistance torque in response to flexion of the first link and the second link relative to each other and 
 when the manual tab is in the second position, the second end of the force generator is disengaged the second link, and the first link and the second link are free to flex and extend relative to each other. 
 
 
     
     
       22. The leg apparatus of  claim 21 , wherein the manual tab is configured to slide on the second link and relative to the second link between the first position and the second position. 
     
     
       23. The leg apparatus of  claim 21 , wherein one of the first link or the second link is configured to be coupled to a thigh of the wearer. 
     
     
       24. The leg apparatus of  claim 21 , wherein one of the first link or the second link is configured to be coupled with a shank of the wearer.